Improvement in the manufacture of screw-thread cutters



T. T. NASH.

I Manufacture of'Screw Thread-Cutters No.168.577.

Patented 0ct.11.,l875

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UNITED STATES PATENT QFFIOE.

THOMAS T. NASH, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN THE MANUFACTURE OF SCREW-THREAD CUTTERS.

Specification forming part of Letters Patent No. 168,577, dated October 11, 1875; application filed September 20, 1875.

To all whom it may concern Be it known that I, THOMAS T. NASH, of the city and county of Philadelphia, in the State of Pennsylvania, have invented an Improved Mode of Making Detachable Chasers, of which the following is a specification My invention relates to the construction of the detachable'cutters, such as shown in my application filed August 27, 1 87 5 and consists in the formation of ahollow cylinder, in which a screw-thread is cut from end to end, and annular dovetails formed on its periphery, at suitable distances apart, to form the proper width of the cutters when the cylinder has been sep arated into separate rings. The rings are then cut into pieces of a proper length for the cutters. By this means the cutters are very expeditiously and cheaply made.

If desired, instead of prolonging the cylinder of sufiioient length to form a plurality of rings, it may be only of sufficient length for a single ring.

1n the accompanying drawings, Figurel is an end view of the cylinder, having a screwthrea-d cut in its inner surface, and dovetails formed on its periphery. Fig. 2 is a side view of the same. It is broken away at a, to show the screw threads, which extend the whole length of the cylinder. Fig.3 is an edge view of one of the rings B severed from the cylinder. Fig. at is an end view of the same, with a portion cut out to form the cutter. Fig. 5 is an isometrical view of the cutter (J.

Like letters of reference in all the figures indicate the same parts.

A is a hollow cylinder, which has threads length, a portion being represented at m, where the side of the cylinder is broken away for that purpose, On the periphery of the cylinder are formed annular dovetails a, of such distance apart that when the cylinder is separated, by means of a turning-tool, into rings B, as begun at the right-hand end, they shall be of the proper length for the cutters. An edge view of a ring, B, severed from the cylinder A, is shown in Fig. 3. The ring is marked off into equal parts of the requisite length for the cutters, as shown in Fig. 4, in which one of the pieces has been separated from the ring to form the cutter 0. (Shown in. Fig. 5.) After the cylinder is constructed with its threaded internal surface, and a series of annular dovetails on its periphery, it may be separated, if desired, into cutters 0 (represented in on its periphery, and a threaded internal surface, and separating it into pieces of suitable dimensions to form cutters U, substantially as described.

THOMAS T. NASH.

Witnesses:

THOMAS J. BEWLEY, STEPHEN USTIGK. 

